A digital data processing system normally comprises a number of devices which are interconnected to enable information to be transferred thereamong for processing, storage, display, printing and the like. A number of interconnection arrangements have been used in digital data processing systems. In one particular arrangement, in which information is transferred using the well-known Fibre Channel protocol, the devices are connected in a ring topology, in which device DEV(1) transfers information to device DEV(2), and so forth. The last device DEV(L) in the ring transfers information to the first device DEV(1), thereby completing the ring. A ring interconnection using the Fibre Channel protocol has a number of advantages, most notably the fact that information can be transferred very rapidly, in particular up to the gigabit-per-second range.
There are several disadvantages, however, to the use of a ring interconnection topology. One disadvantage is that adding devices to a ring interconnection can be difficult and lead to failures. In addition, if a device fails, information transferred through the interconnection, can be stopped or corrupted, depending on the cause of the failure, and locating the particular failing device and isolating the device can be difficult.